Conventional color photography depends on the imagewise formation of dyes and uses subtractive primaries to form the desired colors. Yellow, magenta, and cyan dyes are conventionally formed during photographic processing from dye-forming coupler compounds upon reaction with oxidized color developer. Each dye-forming coupler desirably provides good reactivity, while the formed dye desirably exhibits good stability. One of the typical problems encountered with many dyes formed from coupler compounds, e.g., is their tendency to degrade when exposed to light. This is of particular importance with respect to photographic elements intended for direct or projection viewing. Such elements include reflective prints and color transmission elements such as motion picture prints and projection slides. Such elements receive substantial exposure to light while being viewed. This not only causes the dye images to fade, but when the dyes of different colors fade at different rates, the image changes color and the neutral areas become undesirably colored.
Since the advent of color photography there have been ongoing efforts to provide yellow dye-forming couplers with improved properties, including reactivity, formed dye hue and dye stability. Typical yellow image dye-forming couplers are described in such representative patents and publications as: U.S. Pat. Nos. 2,875,057; 2,407,210; 3,265,506; 2,298,443; 3,048,194; 3,447,928 and "Farbkuppler - Eine Literature Ubersicht," published in Agfa Mitteilungen, Band III, pp. 112-126 (1961). Such couplers are typically open chain ketomethylene compounds. Frequently, yellow coupler compounds may provide advantageous results with respect to one property, while less than desired results with respect to others. Accordingly, it would be desirable to provide a new class of yellow image dye-forming couplers, especially a new class of such couplers which provides an advantageous combination of such properties.
Thus it is an object of the invention to provide a new class of yellow dye-forming coupler that exhibits good reactivity during photographic processing, as well as forming a dye having good resistance to light degradation.